#include <iostream>
using namespace std;
bool isPrimeNumber(int num)
{
	if (num < 2) {
		cout << "非法输入！" << endl;
		return false;
	}
	int sqrt_num = int(sqrt(num));
	for (int i = 2; i <= sqrt_num; i++) {
		if (num % i == 0)    return false;
	}
	return true;
}
void DecodeEvenToPrime(int num)
{
	for (int even = num / 2 * 2; even >= 6; even -= 2) {
		for (int i = 3; i <= even / 2; i++) {
			int j = even - i;
			if (isPrimeNumber(i) && isPrimeNumber(j)) {
				cout << "偶数" << even << "的素数分解结果: " << even << " = " << i << " + " << j << endl;
			}
		}
	}
}
int main()
{
	cout << "请输入一个整数N (N>=6):";
	int n;
	cin >> n;
	if (n < 6)    cout << "输入非法" << endl;
	else    DecodeEvenToPrime(n);
	system("pause");
	
	return 0;
}